Restricted use of AT commands in Multiplex mode, Ate

AT Command Set

turns to the AT command mode.

3.There are various options to switch from data mode to command mode:

a)Escape sequence +++

b)Circuit 108/2 (DTR) changes from ON to OFF, reaction depends on command at&d (caution if AT&D0: TA ignores status on DTR).

c)The message Modem Status Command (MSC) for control channel is defined by the multiplexer protocol GSM07.10. MSC conveys V.24 signals. Bit 3 of Control Signal Octet is DTR, reaction depends on command at&d (caution if AT&D0: TA ignores status on DTR).

4.The parameter maximum frame size (N1) of AT+CMUX in GSM07.07 is fixed to 97 and cannot be changed. All other parameters are not avail- able.

5.Multiplex mode can be terminated by AT^SMSO (,AT^SMSO Switch off mobile station" pg. 191). It has to be reestablished after power-on.

4.28.1Restricted use of AT commands in Multiplex mode

In Multiplex mode, the operation of several AT commands varies from the normal mode. This chapter summarizes the concerned commands. For general rules and restrictions to be considered in Multiplex mode please refer to [5].

Data, fax and GPRS calls can only be set up on logical channel 1. Due to this restriction, AT com- mands have a different behaviour on channels 2+3 compared to channel 1. Several commands are not available, others return different responses. These commands are listed in the table below:

Table 6: Availability of AT commands on virtual channels

Command	Behaviour on channel 1	Differences on channel 2+3
+++	as described	not usable
ATE	as described	as described
AT+CBST	as described	not usable
AT+CR	as described	not usable
AT+CRLP	as described	not usable
AT+CG... (GPRS commands)	as described	usage not recommended 2)
AT+F.... (Fax commands)	as described	not usable
AT&C	as described	not usable
AT&D	as described	not usable
AT&F	as described	data call parameters not changed
		S3, S4 not changed

AT&S	as described	not usable
AT&V	as described	data call parameters not displayed
ATA	as described	no data calls
ATD	as described	no data calls
ATDI<n>	as described	not usable
ATO	as described	not usable
ATS0 1)	as described	not usable
ATS3 1)	as described	as described

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02.04.2002

MC35 specifications

The Siemens MC35 is a compact and versatile modem designed primarily for mobile communication, data transmission, and machine-to-machine (M2M) applications. Launched in the early 2000s, it quickly became popular due to its blend of performance, reliability, and ease of integration, making it a solid choice for developers and businesses.

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To summarize, the Siemens MC35 stands out as a reliable modem with a rich feature set that includes GSM and GPRS support, SMS and voice capabilities, easy integration through various interface options, and energy-efficient operation. Its adaptability makes it a valuable tool for a wide array of communication and data transmission tasks, solidifying its place in the evolution of mobile communications technology.

Siemens MC35 manual Restricted use of AT commands in Multiplex mode, Ate, At+Cr, At&D

Models: MC35

4.28.1Restricted use of AT commands in Multiplex mode

Command

Behaviour on channel 1

Differences on channel 2+3

ATE

AT+CBST

AT+CR

AT+CRLP

AT&D

ATA

ATO

MC35 specifications